\begin{table}[!htb]\centering                  \def\sym#1{\ifmmode^{#1}\else\(^{#1}\)\fi}                   \caption{Composition effects resurfacing\label{tab:composition_Q}}                 \setlength{\tabcolsep}{1pt}                                                                                                                                                                  \begin{tabular}{l*{7}{c}}\hline\hline \bigskip\\[6ex]
                &\multicolumn{1}{c}{\LongHead{15ex}{AADT}}&\multicolumn{1}{c}{\LongHead{15ex}{HPMS Urban}}&\multicolumn{1}{c}{\LongHead{15ex}{NLCD Urban}}&\multicolumn{1}{c}{\LongHead{15ex}{Rigid surface}}&\multicolumn{1}{c}{\LongHead{15ex}{Structural Number}}&\multicolumn{1}{c}{\LongHead{15ex}{Unionization}}\\
\hline
\( \mathds{1}_{ist}(q)\imath^q_{st}\)& -1076.50\sym{***}& -1005.20\sym{***}& -1662.48\sym{***}&  -928.00\sym{***}&  -635.53\sym{**} & -1849.20\sym{***}\\
                & (127.36)         & (126.08)         & (220.56)         &  (99.31)         & (195.73)         & (252.40)         \\
\( \mathds{1}_{ist}(q)\imath^q_{st}\) \(\times\) \(t\)&    28.56\sym{***}&    25.19\sym{**} &    55.60\sym{***}&    26.27\sym{***}&    14.34         &    92.81\sym{***}\\
                &   (8.58)         &   (8.22)         &  (15.46)         &   (7.33)         &  (13.81)         &  (16.83)         \\
\(t\)            &     0.04         &     0.00         &    -0.00         &     0.05         &     0.00         &    -0.03         \\
                &   (0.08)         &   (0.08)         &   (0.08)         &   (0.08)         &   (0.08)         &   (0.13)         \\
\(x^0\)       &    -0.38\sym{+}  &                  &                  &     3.54\sym{**} &     0.37         &    -0.09         \\
                &   (0.20)         &                  &                  &   (1.17)         &   (0.32)         &   (0.42)         \\
\(x^0\) \(\times\) \( \mathds{1}_{ist}(q)\imath^q_{st}\)&    24.58\sym{+}  &    26.98         & 4,504.98\sym{***}&  -346.82\sym{*}  &   -53.77\sym{+}  &    50.12\sym{***}\\
                &  (14.62)         & (136.38)         & (980.24)         & (168.65)         &  (31.92)         &  (13.32)         \\
\(x^0\) \(\times\) \( \mathds{1}_{ist}(q)\imath^q_{st}\) \(\times\) \(t\)&    -0.29         &    10.68         &  -166.79\sym{*}  &    19.88         &     2.39         &    -3.79\sym{***}\\
                &   (0.92)         &   (9.45)         &  (75.38)         &  (12.37)         &   (2.12)         &   (0.93)         \\
\cline{2-7}Segment id FE   &      Yes         &      Yes         &      Yes         &      Yes         &      Yes         &      Yes         \\
\hline
N               &  181,236         &  181,236         &  181,236         &  181,068         &  181,236         &  181,236         \\
\hline\hline                 \multicolumn{7}{m{0.9\textwidth}}{ \footnotesize \noteSampleComposition Standard Errors in Parentheses Clustered at the State-Year Level. \sym{+} \(p<0.10\), \sym{*} \(p<0.05\), \sym{**} \(p<0.01\), \sym{***} \(p<0.001\). }                 \end{tabular}\end{table}
